Texas mountain laurel

For the Low Desert

March is prime planting time for low-desert gardeners. While perusing nurseries and botanical garden sales, be careful not to judge a plant by its container size. Desert plants often appear unimpressive in nursery pots, but once transplanted into the ground they grow rapidly. Choose plants based upon their mature size, so that they don’t overreach your landscape’s available vertical and horizontal spaces. (As an example of speedy growth, check out Mary Bossler’s palo verde tree on Page 65 that she planted from a 5-gallon pot.)

Factor in the size of a tree’s canopy and root spread. Be sure the canopy won’t shade veggie beds; drape over swimming pools, spas and air-conditioning units; or trespass on your neighbor’s lot. As a guideline, tree roots spread at least as wide as the canopy and up to four times beyond. In limited spaces, use small trees or large shrubs, because smaller root systems are less likely to damage the hardscape.


WHAT TO PLANT
• Desert-adapted landscape plants—Transplant trees, shrubs, vines, ground covers, perennials, ornamental grasses, cacti and succulents.
• Small-stature trees—Evergreen thornless choices include (height by  width): cascalote (Caesalpinia cacalaco ‘Smoothie™’), 15'-18' x 15'-18'; mulga (Acacia aneura), 18' x 18'; Silver Peso Texas mountain laurel (Sophora secundiflora ‘Silver Peso’), 15' x 15' (slow growing); Texas olive (Cordia boissieri), 10'-25' tall and wide (also can be grown as a shrub).
• Citrus—For small yards or containers, choose dwarf trees grafted on ‘Flying Dragon’ rootstock. Fruit yield is about 50 to 60 percent of standard-size trees, which is plenty for most households. Also, fruit is easier to harvest from shorter trees.
• Artichokes—The striking silvery foliage of this plant creates an impressive display on its own or as a backdrop for brightly colored flowers. Transplant in garden soil improved with compost. Artichokes are perennial but often are treated as annuals to avoid their having to be nursed through the heat of summer. If you plan to keep them growing, they prefer full sun yet benefit from afternoon shade as summer approaches. Allow space for mature plants to reach up to 4 feet tall and 6 feet wide.
• Warm-season veggies—Transplant eggplant, pepper and tomato plants. Sow seeds for lima and snap beans, corn, cucumber, jicama, melons and squash.
• Cool-season veggies—Sow seeds for a late-season crop of fast-maturing salad fixings, such as baby leaf lettuce, carrots, green onions, radishes and spinach.
• Roses—Continue transplanting modern and old garden (heritage) container-grown roses.
• Herbs—Transplant basil, bay, chamomile, chives, epazote, feverfew, lavender, lemon balm, lemon grass, lemon verbena, oregano, rosemary, sage and santolina.

GARDEN MAINTENANCE
• Monitor forecasts—Be ready to protect tender plants from a late-season freeze. March 15 is the average last frost date in the Phoenix area, although this varies depending on elevation, microclimate and weather.
• Monitor water use—Reset timers as needed to gradually increase irrigation frequency as temperatures warm.